Budget airline Ryanair's battle with the Advertising Standards Authority has escalated today, with both sides submitting formal complaints to the Office of Fair Trading.

Ryanair has also publishing extensive communications with the ASA on its website today.

The Irish airline has been battling the ASA over a series of ads the regulator ruled were in breach of its advertising code.

The most recent clash was over an ad featuring a Britney Spears-style schoolgirl that was banned by the regulator in January because it linked schoolgirls with sexually provocative behaviour.

A Ryanair spokesman said the company had submitted a formal complaint to the OFT regarding the "unfair procedures, bias and factually untrue rulings" made against seven of its ads in the last two years.

"We are calling on the OFT to examine this catalogue of maladministration, bias and incompetence by the ASA, and require in future that the ASA rules on Ryanair's adverts in an independent, impartial, fair and reasonable manner," the spokesman added.

"Fairness and impartiality is the least that advertisers should be entitled to expect from an unelected, self-regulating quango like the ASA and its impartial director general. Sadly Ryanair has received neither over the past two years from the ASA."

The airline has added a prominent link to its home page labelled "Ryanair & ASA - the truth", linking to copies of 22 emails and letters.

Ryanair's move follows the ASA's decision today to refer the airline to the OFT.

A spokeswoman from the ASA confirmed that the correspondence on the Ryanair site was genuine, adding that the airline had acted after being informed that it was being referred to the OFT.

"Ryanair has a poor compliance record and consistently fails to act on ASA rulings. Within the regulatory system there is the backstop of passing cases to the OFT when companies regularly break our codes," she said.

"Ryanair missed out one crucial round of correspondence where we gave them a further opportunity to provide the evidence that we required of them."

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